Basic question on retain/release semantics from Apple's reference library
Posted
by davetron5000
on Stack Overflow
See other posts from Stack Overflow
or by davetron5000
Published on 2010-04-11T18:23:18Z
Indexed on
2010/04/11
18:43 UTC
Read the original article
Hit count: 268
I have done Objective-C way back when, and have recently (i.e. just now) read the documentation on Apple's site regarding the use of retain
and release
. However, there is a bit of code in their Creating an iPhone Application page that has me a bit confused:
- (void)setUpPlacardView
{
// Create the placard view -- it calculates its own frame based on its image.
PlacardView *aPlacardView = [[PlacardView alloc] init];
self.placardView = aPlacardView;
[aPlacardView release]; // What effect does this have on self.placardView?!
placardView.center = self.center;
[self addSubview:placardView];
}
Not seeing the entire class, it seems that self.placardView
is also a PlacardView *
and the assignment of it to aPlacardView
doesn't seem to indicate it will retain a reference to it. So, it appears to me that the line I've commented ([aPlacardView release];
) could result in aPlacardView
having a retain count of 0 and thus being deallocated. Since self.placardView
points to it, wouldn't that now point at deallocated memory and cause a problem?
© Stack Overflow or respective owner